It is well known by those skilled in the art of memory storage that the phenomenon of memory fragmentation results in the relatively inefficient utilization of memory space, since unused memory storage locations will become interspersed throughout occupied memory locations of the memory space as fragmentation ensues. This results in the overall storage area in a fragmented memory space being higher than the overall storage area that would ordinarily be obtained by aggregating the occupied memory locations. The process of defragmentation of a memory space is intended to populate the unused memory storage locations as aforesaid with the contents of occupied memory locations, resulting in a compacting of the occupied memory locations and typically in a reduction of the overall storage area exhibited thereby.
Where storage memory architectures are utilized in the field of networked communications, for instance in a telecommunications node such as a switch, fragmentation results generally in a decreased efficiency of memory utilization during the operation of the switch. A storage memory architecture may be shared by different traffic flow types, connection types or call types. For instance, a memory pool may be shared by both ATM and MPLS connections, and such connection types will be associated with different unit storage sizes. As a result, fragmentation in the memory pool can be expected to take place as connections are established and released. In the particular case of MPLS connections being assigned to a given volume of memory, such connections themselves would have storage requirements that are variable in size. Again, fragmentation can be expected to occur as MPLS connections with variable storage requirements are established and released.
Oftentimes, a certain volume of memory in the form of a memory limit may be allocated to different types of connections traversing a switch. In such instances, memory fragmentation may also result in the memory limit for a connection type to be met in less than the most cost effective manner, since a larger proportion of the memory limit will become occupied by unused memory locations as the memory becomes progressively more and more fragmented. As well, if it is intended to change the memory limits respectively allocated to the different connection types as aforesaid, this may become more difficult to accomplish while a switch is operating due to ensuing fragmentation.
Although it is known in the art of communications networks to defragment memory while it is in use, the in-service real time performance of the telecommunications switch may be degraded while defragmentation is taking place. This may result in longer set-up times for the establishment of network connections. There is also some risk that connection information which is stored in the memory architecture may be lost during the defragmentation process if it takes place while the memory is in use. This may potentially result in dropped network connections. Moreover, the larger the memory employed, the longer the duration of the defragmentation process, with the result that the potential for foregoing problems to take place is heightened.
There is therefore a need for a memory architecture which enables defragmentation while alleviating some or all of the problems associated with the known memory architectures discussed above.